Find and run main classes programatically

Hello everyone,

I need to find programatically all main classes in my project.
My project contains multiple server configurations and I am developing a plugin to add actions to the popup menus to start these servers.
A server is started via it's main method. Each server imports a BaseServer class to execute a static method call on it.

Currently, I am collecting all possible servers with the following:

  Collection<VirtualFile> files = FileTypeIndex.getFiles (JavaFileType.INSTANCE, getSearchScope (module));

  PsiManager manager = PsiManager.getInstance (module.getProject ());
  return files.stream ()
              .filter (f -> !f.isDirectory ())
              .map (manager::findFile)
              .filter (Objects::nonNull)
              .filter (this::importsBaseServer)
              .toList ();

I.e. I am traversing each Java file (>500), and check on each import statement if the base class is being imported.

However, that seems very inefficient and results in UI freezes of multiple seconds.
I wondered if there is any better solution to find only the executable Java files?

I found 

JavaExecutionUtil.findMainClass ()